Poly(aryl ether sulfones) have been known for about two decades; they are tough linear polymers that possess a number of attractive features such as excellent high temperature resistance, good electrical properties, and very good hydrolytic stability. Two poly(aryl ether sulfones) are commercially available. A poly(aryl ether sulfone) is available from Imperial Chemical Industries Limited. It has the formula (1) ##STR1## and is produced by polycondensation of 4-(4'-chlorophenylsulfonyl)phenol, as described in British Patent Specification No. 1,153,035. The polymer contains no aliphatic moieties and has a heat deflection temperature of approximately 210.degree. C. Another commercial poly(aryl ether) is available from Amoco Performance Products, Inc. under the trademark UDEL. It corresponds to formula (2) and has a heat deflection temperature of about 180.degree. C. ##STR2##
Polymer (2) is prepared via the nucleophilic polycondensation reaction of 2,2-bis(4-hydroxy-phenyl)propane ("bisphenol-A") with 4,4'-dichlorodiphenyl sulfone. This method, described by Johnson et al., Journal of Polymer Science, A-1, Vol. 5, 1967, pp. 2415-2427, and Johnson et al., U.S. Pat. Nos. 4,107,837 and 4,175,175, has been shown to be quite general and applicable for the synthesis of a broad range of other poly(aryl ether sulfones) (hereinafter called PAE's). Using this approach, a host of PAE's having wide ranging properties was prepared.
Materials (1) and (2) display relatively low glass-transition and, hence, low heat distortion temperatures. The drawback is serious, since it makes the two polymers unsuitable in applications where a high Tg is important. Such applications include, for example, the area of composites which often require a matrix capable of maintaining structural integrity at relatively high temperatures. Thus, over the years, numerous poly(aryl ether sulfones) having high Tg's have been prepared. Of particular interest among these latter polymers are those containing the 4,4'-bis-(phenylsulfonyl)biphenyl units (3): ##STR3## Thus, U.S. Pat. No. 3,647,751 depicts polymers of formula (4): ##STR4## wherein Ar is defined as a diphenylene or naphthylene radical or a polynuclear divalent radical of the formula: ##STR5## where Z is a divalent aliphatic, cycloaliphatic or arylaliphatic radical containing 1 to 8 carbon atoms or --O--, --S--, --SO--, --SO.sub.2 --, or --CO--.
U.S. Pat. No. 3,634,355 describes a number of polymers prepared from 4,4'-bis(4-chlorophenylsulphonyl)biphenyl (5). ##STR6##
For instance, in Example 5 the following polymer is provided: ##STR7##
Example 16 depicts the polymer containing units (6) and (7) is a 4:1 molar ratio. ##STR8##
Example 17 shows the same structure, except that units (6) and (7) are present in a 1:1 ratio.
The homopolymer (7) is described in U.S. Pat. No. 4,009,149.
Copolymers containing units (3) are also the subject of two patent applications (U.S. Ser. Nos. 701,234 and 701,306), both filed on Feb. 13, 1985 in the names of James Elmer Harris, Louis Michael Maresca and Markus Matzner, both titled "Polyaryl Ether Sulfone Polymers", and both commonly assigned.
Other poly(aryl ether sulfones) displaying high glass transition temperatures are, for example, those containing terphenylene, naphthylene, anthracenylene and fluorene-9,9-bis(phenylene) units (8): ##STR9##
The above listed high Tg materials have generally high melt viscosities and are difficult to melt-fabricate. The development of compositions with improved melt flow properties and better melt-fabricability based on the aforementioned high Tg poly(aryl ether sulfones) is, therefore, of great practical importance. It is, of course, necessary that the novel compositions retain the attractive features of the original polymers. Products satisfying the above listed criteria are the subject of the instant invention.